• Journal of Life Science
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• v.33 no.1
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• pp.91-101
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• 2023

Bacteriocins are antimicrobial peptides synthesized on ribosomes, produced by bacteria, that inhibit the growth of similar or closely related bacterial strains. Since the discovery of nisin, many bacteriocins with unique structures and various modes of antibacterial activity have been described, and genes encoding production, secretion, and immunity have been reported. Nisin is one of the bacteriocins applied in cheese, liquid eggs, sauces and canned foods. Many of the bacteriocins of the genus Bacillus belong to lantibiotics, which are modified peptides after translation. Other genus Bacillus also produce many non-lantibiotic bacteriocins. Bacteriocins of the genus Bacillus are sometimes becoming more important because of their broader antibacterial spectrum. Bacteriocins are considered attractive compounds in the food and pharmaceutical industries to prevent food spoilage and growth of pathogenic bacteria. Bacteriocins can be used as biological preservatives in a variety of ways in the food system. Biopreservation refers to extending shelf life and improving safety of foods using microorganisms and/or their metabolites. The demand for new antimicrobial compounds has generated great interest in new technologies that can improve food microbiological safety. Applications of bacteriocins are expanding from food to human health. Today, many researchers are shifting their interest in bacteriocins from food preservation to the treatment of bacteria that cause infections and antibiotic-resistant diseases. This exciting new era in bacteriocin research will undoubtedly lead to new inventions and new applications. In this review, we summarize the various properties and applications of bacteriocins produced by the genus Bacillus.

• Korea Trade Review
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• v.43 no.5
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• pp.139-158
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• 2018

As trade volume increases and the business environment becomes more complex and competitive, international trade disputes are also increasing and becoming more complex. Parties need to become more aware of alternatives to costly and time consuming arbitration and litigation. The ADR (Alternative Dispute Resolution) can encompass all dispute resolution processed and can act as a substitute for traditional litigation. Mediation, a type of ADR, offers an amicable dispute settlement mechanism between concerned parties through a natural mediator. There are several strong points of mediation compared with litigation or arbitration. First of all, mediation can take place without having to complete time-consuming and expensive discovery processes associated with litigation. In addition, since mediation is considered a private process, the dispute can remain out of the public eye. It can be embarrassing and disrupt business when customer or suppliers learn that a company is involved in litigation. Lastly, mediation is less adversarial than litigation or arbitration, so the parties often can salvage their relationships. Often the parties to mediation find themselves continuing to conduct business. In spite of such benefits of mediation, it is less used in Korea and therefore, this article aims to promote the mediation system in international trade disputes. However, this paper has limitation, for example, why ADR is not used well in Korea and need to suggest how ADR can work best in international trade disputes.

• Journal of the Korean Society for information Management
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• v.40 no.2
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• pp.211-241
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• 2023

With rapidly changing technological implementation of operating systems of businesses, the Ministry of foreign affairs (MOFA) of the Republic of Korea (ROK) has been undergoing digital transformation to its overall operations with the intent to innovate information and knowledge management (IKM) strategies since the mid-2000s. However, assessment as to the effectiveness of implemented IKM has been inadequately analyzed. This study aims to assess the concepts and limitations of the MOFA's current IKM strategies and the methods it employs to deliver its IKM framework, in light of strengthening the organizational ambidexterity and absorptive capacity, and also fostering organizational innovation through a qualitative study that involves interviews and analysis of reports from MOFA. The MOFA's IKM possesses dynamic capabilities to adapt to changing digital technologies. However, the institution's IKM is constrained by limitations associated with the utilization of the IKM system such as a structure that handles confidential documents and a lack of a collaborative system for IKM, and external limitations such as changes in the domestic political situation governing MOFA's priorities and the hierarchy of government organizations. Consequently, developing the organizational ambidexterity and absorptive capacity was not possible. To develop an IKM framework for organizational innovation, the MOFA must devise a way to minimize the impact of external changes by overcoming internal limitations. To that end, a detailed study on the development of a practically usable IKM system should include establishing a dialogue between job groups and enhancing employee competency in preparation for a changing environment.

• Information Display
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• v.23 no.4
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• pp.12-21
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• 2022

반도체 기반 양자점 (QD)소재와 CsPbX3 (X=Cl, Br, I)기반 perovskite 양자점 또는 나노결정 소재(PNC)는 매우 우수한 양자효율과 좁은 발광 선폭으로 고색재현성 디스플레이 색변환 소재 또는 발광 소재로서 각광을 받고 있다. 그러나, 기존 화학적 합성법을 통해 제조되는 QD 및 PNC 소재는 취약한 열 및 화학적 안정성으로 인해 장기 내구성의 개선이 요구된다. 이들 QD 및 PNC 소재는 모두 완전 무기 소재인 산화물 기반 유리 소재내에 생성이 가능하며, 이를 통해 장기 내구성을 근본적으로 개선할 수 있다. 반도체 기반 QD 함유 유리소재 (QDEG)의 경우, 유리 내 core/shell 구조를 가진 QD의 생성으로 양자효율의 향상이 가능했으나, 콜로이드 기반 양자점 (cQD)과 달리 다중 shell의 형성이 어려워 양자효율이 제한되고, 발광 선폭이 넓어 고색재현성 디스플레이용 색변환 소재로 적용되기에는 아직 한계가 있다. 한편, Perovskite 양자점 (또는 나노결정) 함유 유리소재 (PNEG) 소재는 QDEG과 달리 콜로이드 기반의 PNC (c-PNC)가 가지는 우수한 양자효율과 20 nm 수준의 좁은 선폭을 유리 내에서도 가지며, c-PNC 대비 열적, 화학적 및 광학적 안정성이 획기적으로 향상되어 실질적인 응용 가능성을 높이고 있다. 특히, 일반적인 용융-급랭법으로 제조하여 대량생산에 용이하고, 분말 또는 판상 등 다양한 형태로의 제작이 가능한 장점이 있다. 현재까지 제조된 PNEG의 최대 PL-QY는 450 nm 여기 시 녹색 및 적색에서 약 60% 수준이며, Al₂O₃ 분말을 이용할 경우 최대 80% 수준까지 달성이 가능하다. 또한, PNEG과 blue LED를 이용하여 백색 LED를 구현할 경우 color filter를 적용하지 않을 때, NTSC 대비 최대 약 130 % 수준의 높은 색재현 영역을 보여 주고 있으며, 실제 LCD용 BLU로 적용 시 기존 상용 c-QD 소재와 동등 이상의 색재현 영역을 보이고 있어, 실질적인 응용 가능성이 매우 높음을 확인하였다. PNEG의 상업적인 응용을 위해서는 몇 가지 추가적인 연구 개발이 필요하다. 기존 c-QD 또는 c-PNC는 나노 수준 크기의 입자가 액상에 분산된 형태로 입도 제어가 용이하나, PNEG의 경우 분말 제조 시 유리 형성 후 분쇄를 통해 제조되며, 입도가 대개 수십 ㎛ 이하로 작아질 경우 PL-QY가 저하되어, 향후 잉크젯 공정 응용을 위해서는 고효율의 분말 제조공정 개발이 필요하다. 또한, 유리 소재의 경우 절연체로서 기존 QD 소재 대비 electro-luminescence(EL) 소자의 활성층으로 사용하는데 제약이 있어 PNEG을 이용한 EL 소자 제작에 대한 연구도 필요하다. 마지막으로, 기존 c-PNC 소재와 같이 Pb가 함유되지 않은 PNEG 소재의 개발이 선결되어야 할 것으로 판단된다. 이와 같은 해결 과제들에도 불구하고, PNEG 소재는 기존 c-QD 소재 대비 매우 우수한 안정성을 기반으로 고품위 고색재현 디스플레이용 색변환 소재로서 다양한 응용에 활용될 수 있을 것으로 기대된다.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.7
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• pp.303-314
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• 2023

Voice conversion, a technology that allows an individual's speech data to be regenerated with the acoustic properties(tone, cadence, gender) of another, has countless applications in education, communication, and entertainment. This paper proposes an approach based on the StarGAN-VC model that generates realistic-sounding speech without requiring parallel utterances. To overcome the constraints of the existing StarGAN-VC model that utilizes one-hot vectors of original and target speaker information, this paper extracts feature vectors of target speakers using a pre-trained version of Rawnet3. This results in a latent space where voice conversion can be performed without direct speaker-to-speaker mappings, enabling an any-to-any structure. In addition to the loss terms used in the original StarGAN-VC model, Wasserstein distance is used as a loss term to ensure that generated voice segments match the acoustic properties of the target voice. Two Time-Scale Update Rule (TTUR) is also used to facilitate stable training. Experimental results show that the proposed method outperforms previous methods, including the StarGAN-VC network on which it was based.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6A
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• pp.977-988
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• 2006

The goal of this study is to develop a realistic methodology for determination of the Life-Cycle Cost (LCC)-effective optimal seismic retrofit and maintenance strategy of deteriorating bridges. The proposed methodology is based on the concept of minimum LCC which is expressed as the sum of present value of seismic retrofit costs, expected maintenance costs, and expected economic losses with the constraints such as design requirements and acceptable risk of death. The proposed methodology is applied to the LCC-effective optimal seismic retrofit and maintenance strategy of a steel bridge considered as a example bridge in the accompanying study, and various conditions such as corrosion environments and Average Daily Traffic Volumes (ADTVs) are considered to investigate the effects on total expected LCC. In addition, to verify the validity of the developed methodology, the results are compared with the existing methodology. From the numerical investigation, it may be positively expected that the proposed methodology can be effectively utilized as a practical tool for the decision-making of LCC-effective optimal seismic retrofit and maintenance strategy of deteriorating bridges.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4D
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• pp.361-368
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• 2010

It is general that mostly congested sections of national backbone networks have been improved based on the national network expansion plan. However, in case of intermodal terminals which are origins of logistics, it is still so congested that travel time between origin and destination is long. Therefore, intermodal transportation systems plan of major intermodal terminals for the intermodal connector networks between intermodal terminal and national backbone network or intermodal terminal was established. With the limitation of priority methodology applying to intermodal connector facility under existing methodology, this study suggests an improved priority methodology. This study includes characteristics of terminal on the hierarchical structure and assessment list, but it does not concentrate on the specific terminal type through survey. To avoid a certain concentration, budget constraint for each terminal type was considered ahead of priority. Finally priority methodology was developed with two-step assessment under consideration that specific terminal is not involved in intermodal connector facility project. As a result of calculating weights by survey, effects such as d/c and accessibility fluctuations index through project implementation gain high weight, and degree of region underdevelopment gets next. Although the methodology in this study could not yields the priority by assessment list, it will be useful for setting the direction on policy related to intermodal connector facility projects.

• Korean Journal of Social Welfare Studies
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• v.41 no.1
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• pp.175-201
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• 2010

The purpose of this study was to examine the mechanism through which youth school-based mentoring program impacts mentees' psychological and school-related outcomes such as self-esteem, self-efficacy, and attitudes toward school. The hypothetical model was assumed that mentors could improve their mentees' developmental outcomes through positive relationships with mentors as good role models and enhancement of help-seeking orientation. To investigate the mediating effect of process-related outcomes, structural equation modeling was used. The 97 adolescents were recruited through referral and random selection from middle schools in Seoul. The result showed that the effects of program participation were mediated by proximal changes in connectedness to role models and development of help-seeking orientation that, in turn, led to facilitate more positive attitudes toward school and academic activity, and improve psychological outcomes. Practice and policy implications as well as further research topics were discussed to aid the search for highly effective mentoring programs.

• Korean Journal of Social Welfare Studies
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• v.42 no.1
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• pp.31-54
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• 2011

This study investigates the nature of the welfare state under the Kim Dae Jung and Roh Moo Hyun regime focusing on participatory democracy in the policy decision making procedure for the National Health Insurance. Participatory democracy was introduced not for the qualitative development of Korean democracy but for securing political legitimacy to change the Korean economic structure after the IMF financial crisis. Although participatory democracy played the positive role in winning higher benefit level in National Health Insurance. an index for the development of the welfare state, in 2007 A policy of higher benefit level ended in failure because of the pursuit of the neoliberal ideology, lack of government's responsibility for public finance, and thwarting policy holders' substantial participation in the decision-making process. Like those of past welfare systems, participatory democracy under the Kim Dae Jung and Roh Moo Hyun regime was introduced for securing political legitimacy. But it was managed under restrictions imposed by pro-economic-growth ideology. Nevertheless, the Kim Dae Jung and Roh Moo Hyun governments are different from the former welfare states because of the fact that participatory democracy system is not 'service' system but 'political structure' and the fact that the grant of powers by participatory democracy played positive roles in the development of welfare state through request of higher benefit level policy.

• Membrane Journal
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• v.33 no.6
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• pp.439-446
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• 2023

Ceramic membranes are generally used for various industrial processes operating under extreme conditions because of its high thermal and chemical stability. However, due to the trade-off phenomenon of permeability and mechanical strength, preparation of high permeability-high strength membrane is necessary. In this study, the change in characteristics and performances of ceramic membranes was analyzed depending on the type of polymer binder and its mixing ratio. Because the solubility between solvent and polymer binder was higher in PSf (polysulfone) than in PES (polyethersulfone), the viscosity and discharge pressure of the PSf-based dope solution were higher than those of PES-based dope solution. When PSf was used as a polymer binder, ceramic membrane showed high mechanical strength and low water permeability due to the dense structure. On the other hand, in case of PES, the mechanical strength was slightly reduced and the water permeability was increased. It was confirmed that the optimum mixing ratio of the PSf and PES with high water permeability and mechanical strength was 9:1.